ConnectionManager: allow to provide RNG through configuration

Change-Id: Ic24123e329b221f5f1e24d3df6f3cc93649c4591
diff --git a/include/connectionmanager.h b/include/connectionmanager.h
index 5a97280..086981f 100644
--- a/include/connectionmanager.h
+++ b/include/connectionmanager.h
@@ -321,6 +321,8 @@
      */
     bool getUPnPActive() const;
 
+    /** Optional pseudo random generator to be used, allowing to control the seed. */
+    std::unique_ptr<std::mt19937_64> rng;
 };
 
 } // namespace dhtnet
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